The present invention is generally directed to a process for obtaining images, and more specifically, the present invention is directed to the formulation of abrasion free and/or abrasion resistant documents with images thereon, which documents can be subsequently selected for utilization in electrostatographic imaging and printing processes. Thus, in one embodiment of the present invention there are provided original documents from electrostatographic imaging or printing processes wherein the images thereon have been permanently fused by, for example, radiant or flash fusing systems; and wherein the original can be subsequently utilized for extended time periods enabling the generation of additional copies therefrom with excellent resolution. Accordingly, thus the process of the present invention in one embodiment enables the generation of an original imaged document with certain developer compositions, which document is subsequently selected for obtaining copies therefrom, for example, in a xerographic imaging apparatus; and wherein the original document is substantially free of abrasion characteristics, and wherein toner flakes are not deposited on the recirculating original document. Moreover, in accordance with the process of the present invention there can be obtained smudge resistant images, that is, images with effective acceptable fixing; and additionally the developer composition selected, in some instances, prevents contamination of machine components such as corotrons present in the imaging apparatus. Furthermore, abrasion resistant image documents and other desirable characteristics illustrated hereinafter are achieved with the process of the present invention, particularly when there is selected for the generation of an original document developer compositions containing therein low molecular weight waxy components. One developer composition selected for the process of the present invention contains therein resin particles, particularly polyester polymers, pigment particles, inclusive of optional magnetite particles, low molecular weight waxy components, and additive particles of colloidal silicas and/or metal salts of fatty acids; and carrier components.
Presently, particularly with radiant and flash fused images, cycling with automatic document handlers incorporated into xerographic imaging or printing apparatuses causes the surfaces of the images to be scraped by, for example, the registration guide. This scraping action permits an undesirable build up of toner flakes on the registration guide, and further continued cycling of the images in the document handling results in transfer of the toner flakes accumulated on the registration guide to the images. Accordingly, when for example the imaged original documents which are generated from xerographic printing apparatuses including the Xerox Corporation 9700.RTM. are selected for further use in electrostatographic imaging processes for the purpose of obtaining additional copies from the original, the aforementioned copies having present thereon enhanced image defects including the presence of undesirable dark bands. These bands on the copies formulated from the original document are generally observed within from about 5 to 10 cyclings of the original radiant or flash fused original document. Specifically, therefore, it is desirable in some instances to select as originals for electrostatographic imaging processes defect free imaged documents or copies which have been initially generated in a xerographic printing apparatus, particularly those having incorporated therein laser printers; and wherein the toner image has been fused to the paper substrate by radiant or flash fusing systems. However, as indicated herein, in most instances the originals when subsequently cycled through document handlers present in xerographic imaging and printing apparatuses are subject to abrasion or scraping by elements of the document handler inclusive of the registration guide thereby permitting the undesirable deposition of toner flakes on the guide, and other machine parts. With continued cycling in the document handler, there results the transfer of the toner flakes which accumulate on the recirculating original image document, thus the copies made therefrom posses several undesirable characteristics including enhanced image defects as mentioned hereinbefore. This problem, as well as other problems as illustrated herein, are substantially eliminated with the process of the present invention, especially when there is selected for the formulation of the original imaged document a toner composition containing therein a low molecular weight wax such as a polyethylene or polypropylene enabling a toner image with a waxy surface. Apparently, although it is not desired to be limited by theory, it is believed that the dark bands and abrasion resistance is enabled by rendering the surface of the radiant or flash fused image document being selected as an original to assume a slippery appearance thereby permitting the image to slide, for example, rather than scrape over the machine components inclusive of the registration guide. This is particularly applicable to printers with lasers therein and wherein radiant and flash fusing processes are selected.
Developer compositions, including magnetic compositions and processes of imaging thereof, are known. There is thus disclosed in U.S. Pat. No. 3,345,294 a developer composition comprised of specific ingredients including, for example a resin, a major portion of which is a polyamide substance having a sharp melting point within the range of from about 70 degrees centigrade to about 165 degrees centrigrade. As disclosed in column 4, beginning at line 34 of this patent, a small amount of finely divided magnetic substance is added to the developer particles to reduce the tendency of the developer powder or toner to adhere to the background of the resulting print. Examples of magnetic substances recited in this patent are magnetic iron oxides, ferrosoferric oxide powders, a magnetic metal substance, or an alloy. The magnetic material is generally present in an amount of between 5 percent and 25 percent by weight, reference the disclosure in column 4, beginning at line 38, of the '294 patent.
Additionally, there is disclosed in U.S. Pat. No. 4,082,681, a magnetic developer for xerographic imaging systems comprised of a magnetic material dispersed in a resinous binder with finely divided solid substances such as conductive carbon black particles. This patent is representative of several patents disclosing the use of magnetic materials in developer compositions. Moreover, there is disclosed in U.S. Pat. No. 4,288,519, the disclosure of which is totally incorporated herein by reference, a specific dual purpose single component conductive magnetically attractive toner containing a mixture of a thermoplastic resin, finely divided magnetic pigments, and anchored conductive pigments, wherein as a resinous substance there can be selected a linear polyester consisting of the condensation product of an aromatic diol with an unsaturated aliphatic dibasic acid having a softening point of from about 95 degrees centigrade to about 150 degrees centrigrade, and an ethylenevinylacetate copolymer. Furthermore, the use of polyester resins as toner components are disclosed generally in U.S. Pat. No. 3,590,000, the disclosure of which is totally incorporated herein by reference.
Moreover, disclosed in U.S. Pat. No. 3,239,465 are two-component developer compositions comprised of specific resin particles and magnetite. According to the disclosure of this patent, reference column 9, beginning at line 56, examples of suitable electroscopic materials selected for the developer composition include phenolformaldehyde resins, rosin modified phenolformaldehyde resins, maleic glyceride, polystyrene, butadiene styrene copolymers, and other substances. There is incorporated into the toner of the '465 patent magnetic substances inclusive of magnetites in amounts, for example, of from about 20 percent to about 70 percent, reference the disclosure in column 10, beginning at line 41. Examples of granular carrier particles that may be selected are outlined in column 12, beginning at line 18, of the '465 patent.
Furthermore, there is disclosed in a copending application U.S. Ser. No. 713,975, entitled Developer Compositions, the disclosure of which is totally incorporated herein by reference, two-component developer compositions comprised of magnetite, a polyester resin, and carrier particles. The copending application is silent with respect to the addition of low molecular weight waxy components to the developer composition, and further there is no appreciation in the copending application relating to preventing the accumulation of toner flakes on a recirculating abrasion resistant original imaged document.
There is also illustrated in U.S. Pat. No. 4,460,672, the disclosure of which is totally incorporated herein by reference, positively charged toner compositions comprised of resin particles, pigment particles, a low molecular weight waxy material, and a charge enhancing additive inclusive of alkyl pyrridinium halides, and organic sulfonate compositions. Furthermore, there is disclosed in this patent the use of magnetic particles which can be present in the toner composition as the only pigment, or may be combined with other pigments such as carbon black. The magnetic pigments such as Mapico Black, according to the teachings of this patent, are generally incorporated into the toner composition in an amount of from about 10 percent by weight to about 60 percent by weight.
Additionally, there is illustrated in U.S. Pat. No. 4,271,248, the disclosure of which is totally incorporated herein by reference, methods for developing magnetic images with magnetic toners comprised of a magnetite material and a polyester; and in U.S. Pat. No. 4,272,600, the disclosure of which is totally incorporated herein by reference, magnetic toners containing, for example, styrene butadiene copolymers and magnetites such as Mapico Black in amounts of from about 40 to about 70 percent by weight.
Although the prior art processes are sufficient for their intended purposes, with some of these methods there is a tendency to contaminate the components present in the xerographic imaging apparatus. Thus, for example, the toner particles tend to separate from the carrier particles prior to, for example, contacting the latent image on the photoconductive member. The separated toner particles are then free to deposit on machine components, and thus contaminate the machine environment thereby resulting in developed images of low resolution or no developed images whatsoever; and causing possible environmental problems. Further, the deposition of the toner particles renders it necessary over a period of time to replace or clean the internal machine components which adds to the cost of maintenance. For example, when unused toner particles deposit on the optical systems present in electrophotographic machines, a latent image corresponding to the original to be copied will not be fully formed, if formed at all, on the photoreceptor surface thereby resulting in a final fused image of very low quality, which in some instances may be unreadable depending on the amount of toner particles deposited. Additionally, in some instances, the resulting images are not completely fixed to the final substrate causing undesirable smudging. Contamination and smudging is substantially eliminated with the process of the present invention in some instances primarily since the magnetic toner particles are prevented from separating from the carrier particles prior to, for example, contacting the latent image, which toner particles separate therefrom as a result of collisions between the toner particles and carrier particles contained in the developer composition with the components of the electrophotographic imaging apparatus.
Accordingly, there is a need for imaging and printing processes that prevent the contamination of internal machine components with toner particles. Furthermore, there is a need for improved imaging and printing processes that prevent the contamination of xerographic imaging apparatus, enable images that are smudge resistant, provide adequate fixing characteristics, and excellent charging properties.
Moreover, there is a need for imaging and printing processes which prevent the accumulation of toner flakes on an original imaged document generated in a xerographic imaging or printing apparatus. More specifically, with cycling, especially in imaging apparatuses with document handlers, there is a need for imaging and printing apparatuses wherein the surfaces of the original images remain unchipped, that is, do not flake off, and continually redeposit on the cycling original document and various transport mechanisms in the document handlers, for example the registration guides. Additionally, there is a need for abrasion resistant original imaged documents that can be selected for the formulations of images for extended time periods in xerographic imaging and printing apparatuses. Also, there is a need for imaging and printing processes wherein the documents selected are prevented from becoming defaced with abraded toner particles in patterns reflective of the geometry of the document handling device utilized. The aforementioned contamination of toner particles results in objectionable copy quality defects on documents generated from originals obtained, for example, from high speed printers such as the Xerox Corporation 9700.RTM.. Furthermore, the imaged originals generated may eventually become useless because of the released toner deposition thereon; and also the toner particles deposited on the transport mechanism within the document handlers incorporated in the electrostatographic imaging apparatus necessitate more frequent servicing of these handlers for the purpose of reducing and/or eliminating undesirable contamination effects. Additionally, there remains a need for imaging and printing processes wherein single, or two-component developer compositions with lubricants therein, and wherein imaged documents generated from an imaged original obtained in a xerographic imaging or printing apparatus are free of the appearance of undesirable dark bands thereon; and further wherein copies generated therefrom have substantially no image defects.